Testosterone Cypionate is one of the many esterified variants of Testosterone available, and is most likely the second most popular esterified variant (the first being Testosterone Enanthate). It is an injectable form of Testosterone with a slow rate of release and a longer half-life. However, the release rates and half-life of both Testosterone Cypionate and Testosterone Enanthate are very much identical and the two compounds are easily interchangeable (for example, an individual can easily run a 10 week cycle of Testosterone and switch between Testosterone Enanthate and Testosterone Cypionate seamlessly). Testosterone Cypionate possesses a half-life of approximately 12 days while Testosterone Enanthate possesses a half-life of approximately 10 days – hardly much difference. The interesting fact about Testosterone Cypionate, however, is that it seems to have a distinct favor of popularity among American bodybuilders and athletes over the Enanthate variant. These distinctions are not extreme, however, and the commonality of use and availability of both variants is almost equal with Testosterone Enanthate ever so slightly more popular. Neither variant possesses any advantages over the other.

Testosterone Cypionate was first created in the mid-1950s, and was released on the prescription drug market under the brand name Depo-Testosterone and manufactured by UpJohn (however, its brand name at first was labeled as Depo-Testosterone cyclopentylpropionate but was shortened for obvious reasons). Unlike Testosterone Enanthate, which is primarily known as an international item, Testosterone Cypionate is known to be the US answer to the Enanthate variant (although Testosterone Enanthate is utilized almost just as equally in the US). Testosterone Cypionate has held such a positive track record that it is in fact still in production by Upjohn (who merged with Pfizer in 2009) today. As Testosterone Cypionate was the American response to the international product Testosterone Enanthate, many American bodybuilders and athletes throughout the 1960s, 70s, and 80s preferred the use of Testosterone Cypionate over the Enanthate variant for no reason other than the support of an American product, very much akin to an issue of pride (once again, the Cypionate and Enanthate variants of Testosterone are both almost 100% identical and there is no practical reason to prefer one compound over the other).

However, there have been very minimal reports of various pateints that prefer Testosterone Cypionate to Testosterone Enanthate if only because of the fact that some individuals tend to respond better at the injection site. A very small percentage of individuals have reported irritated injection sites in response to the Enanthate variant, and find the Cypionate variant to be much easier in terms of the injection site comfort and reaction. Medically, Testosterone Cypionate, like Enanthate, is used primarily for the treatment of androgen-deficient male patients (hypogonadism and andropause). Other although minor uses of Testosterone Cypionate in the medical field included: the treatment of individuals deficient in bone density and strength, treating uncontrollable menstrual bleeding (menorrhagia), osteoporosis treatment, treatment for frail elderly patients and individuals recovering from periods of extensive muscular atrophy. In recent years, just like Testosterone Enanthate, Testosterone Cypionate has been investigated in its use as a male birth control drug at a dose of 200mg weekly.

Testosterone Cypionate in the 1970s, like all anabolic steroids at the time, had undergone a narrowing of approved medical application in its use. The FDA had narrowed its approved medical uses down to the treatment of male androgen deficiency (hypogonadism and andropause). Testosterone Cypionate held an even stronger case for its narrowing of approved applications due to the fact that Testosterone itself is quite the strong androgen unsuitable for use in females and children where other more suitable anabolic steroids (such as Anavar and Primobolan) could be used instead.

Chemical Characteristics of Testosterone Cypionate

As previously mentioned, Testosterone Cypionate is simply Testosterone with the Cypionate ester bound to the Testosterone chemical structure. Specifically ‘Cypionate’ is Cypionic acid, but once bound to Testosterone it is properly referred to in chemistry as an ester bond (or ester linkage). Cypionic acid is chemically bound to the 17-beta hydroxyl group on the Testosterone structure. Esterified anabolic hold a greater degree of solubility in fats, and therefore release slower from the injection site in comparison to un-esterified Testosterone – however, this is not the main reason as to why esters extend the release rate and half-life of the given anabolic steroid it is attached to. The primary reason for the augmentation of its half-life and release rate is due to the fact that when Testosterone Cypionate enters the bloodstream, enzymes will bind to the Testosterone Cypionate molecule and break the bond between the ester and the hormone, which takes a varying amount of time depending on the size of the ester in question. This is why larger esters such as Cypionate, Enanthate, Decanoate, and so forth all possess longer half-lives than the smaller shorter esters such as Propionate, Phenylpropionate, Acetate, etc. Therefore, the end result is that the ester is removed from the hormone via enzymes, and what is left over following this chemical interaction is pure Testosterone that is free to do its work in the body. This process of enzymes cleaving off the ester from the Testosterone molecule is what is ultimately responsible for the slower release rates. Pure Testosterone alone with no ester bonded to it possesses a half-life of approximately 2 – 4 hours. When the Cypionate ester is attached to it, creating Testosterone Cypionate, the half-life of Testosterone is now extended to 12 days, which results in a slower release and activity of the hormone.

Properties of Testosterone Cypionate

Testosterone Cypionate’s attributes and expressive properties follows what any individual would expect from Testosterone preparation, with the exception of the differing release rates and half-lives. It must be made clear right now to the reader that Testosterone is very much literally the original anabolic steroid, which is manufactured endogenously naturally in all humans and in the vast majority of animal species. Two important facts result from this: 1. Testosterone is utilized as the base measurement by which all other anabolic steroids are measured against, and, 2. Because Testosterone is the most natural anabolic steroid already manufactured by the human body, Testosterone is considered the safest anabolic steroid for use, as every individual’s body is already accustomed to the effects of Testosterone only to a lesser degree. Essentially, the use of Testosterone for the purpose of physique and performance enhancement is simply the supplementation of additional Testosterone – this could easily be defined as the practice of administering (either through injection or ingestion) more of a hormone into the body that it already manufactures and utilizes.